Electric candle



Aug. 18, 1964 R. KLOTZ ELECTRIC CANDLE Filed on. 31, 1962 United States Patent Office 3,145,323 ELECTRIC CANDLE Ren Klotz, 9 Rue de Eelloy, Paris, France Filed Oct. 31, 1962, Ser. No. 234,2Q8 Claims priority, application, France, Apr. 16, 1959, 792,241, Patent 1,232,486 1 4 Claims. (Cl. 315-209) The present invention relates generally to electric illumination and specifically to an incandescent electric bulb designed to operate in simulation of candle light. This is a continuation-in-part of my application Serial Number 22,527 filed April 15, 1960, and entitled Electric Candles now abandoned.

It is recognized that the unique soft and flickering illumination produced by a burning candle represents a desirable feature in many lighting instances and it it further recognized that ordinary incandescent or fluorescent lighting often destroys the authentic appearance of a room designed to reproduce styles which predated the appearance of electric illumination. Based upon the fact that genuine candle illumination is expensive, dangerous and in fact does not provide a sufficient level of illumination, many producers have attempted to provide electric light bulbs which generally simulate candle flames. The principal attempt in this area has simply been to provide an ordinary low output electric light bulb which had a generally flameshaped bulb. Although such bulbs were far superior to the mere ordinary light bulb for the purpose intended, the light output was steady rather than flickering in the manner of a candle such that the result in light was identical to that of an ordinary low powered electric light bulb. In order to remedy this defect, means such as bi-metallic flashers were added to the candle-shaped light bulb to provide flickering illumination. Although this was a marked improvement, the constant phase, on-off behavior of the bulbs was far from the erratic flickering demonstrated by a candle.

Therefore, it is an object of the present invention to provide a candle-simulating light bulb which obviates one or more of the failings specified above. Specifically, it is an object of the present invention to provide an electric light bulb which produces illumination in simulation of candle light.

It is a further object of the present invention to provide a flame-shaped electric light bulb wherein the light produced increases and diminishes in random fashion.

In accordance with one illustrative embodiment of the present invention, there is provided an electric light bulb structure housed within a flame-shaped external envelope or bulb. A light-producing filament is mounted within the bulb in series with an intermittently and nonuniformly acting thermal switch. The switch includes a first elongated thermal responsive element and a second elongated thermal responsive element both of which are mounted in substantially parallel relationship in a nonconducting base at one of their respective ends. The securement of the elements to the base permits vibration of the elements with respect to each other and with respect to the base. Contacts are formed at the other ends of each of the elements in cooperating relationship to make and break electrical contact between the elements. A first power lead wire is connected to one side of the filament wire and the other side of the filament wire is connected to one of the elements of the switch. In addition, a second power lead connects the other element of the thermal switch for supplying electric current to the switch and intermittently therethrough to the light producing filament. A heat-producing resistance wire is engaged about one of the elements and is electrically interconnected between the elements for heating said one element when the contacts are disengaged, said resistance wire being of a resistance value to provide a voltage drop across the filament sulficient to produce low-level illumination when said contacts are disengaged. The elements'are sized to vibrate freely upon a break in contact between the contacts of the said other ends of the elements to produce alternative low-level and high-level illumination as said contacts engage and disengage. Adjustment means are provided Within the base of the switch for selectively adjusting the period and amplitude of vibration of the elements.

The above brief description, as well as further objects, features and advantages, of the present invention, will be best appreciated by reference to the following detailed description when taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a sectional and schematic View of the internal construction of a candle-simulating electric light according to the present invention;

FIG. 2 is a partial elevational view of the thermal switch incorporated within the present invention;

FIG. 3 is a sectional view taken along the line 33 of FIG. 4 and looking in the direction of the arrows.

FIG. 4 is an enlarged sectional view illustrating the interconnection between the base and the elongated heat responsive elements;

FIG. 5 is a plan view of the base of the thermal switch according to the present invention; and

FIG. 6 is an exploded View of the base shown in FIG. 5.

Referring now specifically to the drawings, there is shown a candle-simulating electric light adapted for installation in a glass or other light-transmitting bulb. Preferably, the bulb shown in dotted line configuration is formed in the shape of a candle flame. Generally, the candle simulating electric light comprises a light producing filament resistance wire 31, which may be arranged in an inverted V-shape, and a thermal switch wired in series with power lines to the filament 31 which switch is adapted to randomly and intermittenly deliver electric current to the filament to produce a glowing and gently flickering light within the flame-shaped bulb.

As best seen in FIGS. 2 and 4, the thermal switch according to the present invention comprises a non-conducting base 21, generally of cylindrical shape, upon which are mounted a pair of heat responsive elongated elements 22, 23, which are mounted substantially in par allel relationship by securement of the lower ends of the elements 22, 23 within the base 21, with the upper ends thereof in juxtaposed relationship. The elements 22, 23 may be formed of any standard bi-metallic structure which will cause the elements to bend upon the application or" heat, or may be of any other type of conventional heat-responsive material.

The elements 22, 23 are mounted within the base 21 as shown in FIG. 4 by securement within complementary openings extending through the base 21, which complementary openings have enlarged wedge-shaped portions 37, 38 at the upper ends thereof such that the elements 22, 23 are not rigidly engaged with the base 21 at the point at which they extend outwardly therefrom. Set screws 35, 3d are provided to apply adjustable pressure against the elements 22, 23. It will be appreciated that the elements 22, 23 are permitted to vibrate along their lengths with respect to the base 21 and that the amount of vibration may be easily controlled by the relative pressure applied to the elements 22, 23 by the adjustment screws 35, 36.

At the upper ends of the elements 22, 23 there are provided contacts 2 25 in juxtaposed relationship such that upon bending of either of the elements 22, 23 the contacts 24, 25 will engage to form a firm electrical contact therebetween. Deformation of the element 22 is Patented Aug. 18, 1964 araaaea provided by means of a heat producing resistance wire 26 positioned about the lower portion of the element 22. Upon the introduction of an electric current through the wire 26, heat will be generated and, due to the heat responsive characteristics of the material of the element 22, it will bend in a slight are as shown in dotted configuration in FIG. 1 such that the contact 24 will move into engagement with the contact 25. This contact is effective to complete a circuit from a power input line 27 which is engaged with the element 22 at the point at which it extends below the base 21, through the element 22 to the engaged contacts 24, 25, through the second element 23 to a point 29 at the base of the element 23 where contact is made with a connecting wire 30 which is secured to one end of the light-producing filament 31. The other end of the light-producing filament 31 is connected to a further supply lead 32 which, together with the supply lead 27, are placed across a conventional electric power supply. Current is thus delivered to the filament 31.

When the heat produced in the element 22 is suflicient to bring its contact 24 into engagement with the contact 25 on the second element 23, the heat-producing resistant wire 26 is essentially shorted out such. that no further heat is produced. As the element 22 is cooled, by loss of energy to the ambient, it will return to its original shape, thus disengaging the contacts 24, 25. At the moment they disengage, the flexible mounting arrangement of the elements 23, 24 and their basic spring characteristics will cause them to oscillate such that an intermittent rather than sharp break of the contacts 24, 25 will be achieved. Specifically, the oscillations of the two elements 22, 23 will cause the contacts to engage and disengage a plurality of times and in random fashion due to the intermittent cooling and heating of the elements and due to the springy nature of the material of the elements and their mounting geometries. As may be seen in FIG. 1, the circuit to the resistance wire 26 include the supply wire 27 and a portion of the element 26 which is connected to one end of the resistance wire 26, the other end of which is connected to the point 29 at the lower extremity of the other heat responsive element 23. Thus, when the contacts 24, 25 are disengaged, the primary circuit is through the heat resistant wire 26 but when the contacts 24, 25 are engaged, the elements 23, 24 are in parallel with the heat resistant wire 26, thus essentially eliminating the flow of current through the resistance wire 26.

It will be appreciated that the filament 31 will be brightly l-it when the contacts 24, 25 are engaged due to the free flow of current therethrough and that when the contacts are disengaged a low voltage will be placed across the filament 31 due to the relatively high resistance of the heat producing wire 26 such that only low-level illumination will be produced. Furthermore, the contacts of the thermal switch do not separate clearly thus producing an intermittent bright and dim glowing of the filament 31.

As may be seen by comparing FIGS. 5 and 6, the base 21 is formed of two individual units 33, 34 which may be joined together by the interaction of the aligning pins 39, 41 with the complementary pin seats 40, 42. The elements of the heat responsive switch means may be housed within the cylinder 43 in engagement with the plug 21 at one end and a cap 44 at the other end. This housing 43, 21, 44 produces a closed environment for the two heat responsive elements 22, 23. Although both elements 22, 23 need not necessarily be made of heat responsive material, such construction produces more uniform results since the residual heat retained in and about the element 22 will effect the element 23 in a complementary fashion such that the time characteristics of the switch will not change due to general over-all heating of the environment of the switch. The entire assembly may then be placed with a candle-simulating cylinder, with the bulb positioned at the top. 7

In accordance with the concepts of the present invention there is provided a candle-simulating electric light which will operate to glow brightly and dimly in a manner reminiscent of the flickering of a candle light and will do so in a random fashion also in simulation of the characteristic flame of a candle. Such constructions may be advantageously employed in any one of a variety of installations wherein it is desirable to reproduce the soft and faintly flickering illumination associated with candle light.

The foregoing is a description of just one embodiment of a candle-simulating electric light. Other embodiments may be constructed without departing from the spirit and scope of the invention. Therefore, the following claims should be interpreted broadly in a manner consistent with the spirit and scope of the invention.

What I claim is:

1. A candle-simulating electric light comprising in combination a light-transmitting, flame-shaped bulb, a filament resistance wire mounted within said bulb, an intermittent and non-uniform acting thermal switch including a first elongated thermal responsive element, a second elongated element, a non-conducting base, means in said base for supporting said elements by one of their respective ends in contiguous relationship and for allowing easy vibration of said elongated elements with respect to each other and to said base, a contact at each of the other ends of said elongated elements in cooperating relationship to each other, and a heat-producing resistance wire thermally engaged with one of said elongated elements and electrically interconnected between said elongated elements for producing heat when said contacts are disengaged, said elongated elements being sized to vibrate freely upon a break in contact between said contacts to produce alternate engagement and disengagement of said elongated elements in a random pattern, a first power lead connected to one side of said filament wire, conducting means connecting one of said elongated elements of said switch to the other side of said filament wire, and a second power lead connected to the other of said elongated elements of said thermal switch for supplying electric current to said switch and intermittently to said filament.

2. In a candle-simulating electric light having a lighttransmitting flame-shaped bulb, and a filament resistance wire mounted within said bulb, an intermittent and nonuniform acting thermal switch including a first elonagted thermal responsive element, a second elongated element, a non-conducting base, means in said base for supporting said elongated elements by one of their respective ends in contiguous relationship and for allowing easy vibration of said elongated elements with respect to each other and to said base, a contact at each of the other ends of said elongated elements in cooperating relationship to each other, a heat-producing resistance wire thermally engaged with one of said elongated elements and electrically interconnected between said elongated elements for producing heat when said contacts are disengaged, said elongated elements being sized to vibrate freely upon a break in contact between the contacts at the said other ends thereof, and adjustment means between said base and said elongated elements for selectively adjusting the period and amplitude of vibration of said elements, a first power lead connected to one side of said filament wire, conducting means connecting one of said elongated elements of said switch to the other side of said filament wire, and a second power lead connected to the other of said elongated elements of said thermal switch for supplying electric current to said switch and intermittently to said filament.

3. A candle-simulating electric light comprising in combination a light-transmitting, flame-shaped bulb, a filament resistance wire mounted within said bulb, an intermittent and non-uniform acting thermal switch including a first elongated thermal responsive element, a

second elongated thermal responsive element, a nonconducting base, means in said base for supporting said elongated elements by one of their respective ends in contiguous relationship and for allowing easy vibration of said elongated elements withtrespect to each other and to said base, a contact at each of the other ends of said elongated elements in cooperating relationship to each other, a heat-producing resistance wire thermally engaged with one of said elongated elements and electrically interconnected between said elongated elements for producing heat when said contacts are disengaged, said resistance wire being shorted out when said contacts are engaged, said elongated elements being sized to vibrate freely upon the disengagement as said contacts, and adjustment means between said base and said elongated elements for selectively adjusting the period and amplitude of vibration of said elongated elements, a first power lead connected to one side of said filament wire, conducting means connecting one of said elongated elements of said switch to the other side of said filament wire, and a second power lead connected to the other of said elongated elements of said thermal switch for supplying electric current to said switch and intermittently to said filament.

4. A candle-simulating electric light comprising in combination a light-transmitting,flame-shaped glass bulb, a filament resistance wire mounted within said bulb, an intermittent and non-uniform acting thermal switch including a first elongated bi-metallic, thermal responsive element, a second elongated, thermal responsive element, a non-conducting base, means in said base for supporting said elongated elements by one of their respective ends in contiguous relationship and for allowing easy vibration of said elongated elements with respect to each other and to said base, a contact at each of the other ends of said elongated elements in cooperating relationship to each other, a heat-producing resistance wire coiled about one of said elongated elements and wired between said one elongated element and the other of said elongated elements for heating said one elongated element when said contacts are disengaged, said resistance wire being of a value to produce a sufiicient voltage drop across said filament wire to light same with relatively low-level illumination when said contacts are disengaged, said elongated elements being sized to vibrate freely upon disengagement of said contacts, said contacts reengaging in random fashion as said elongated elements vibrate, and adjustment means between said base and said elongated elements for selectively adjusting the period and amplitude of vibration of said elongated elements, a first power lead connected to one side of said filament wire, conducting means connecting one of said elongated elements of said switch to the other side of said filament wire, and a second power lead connected to the other elongated element of said thermal switch for supplying electric current to said switch and intermittently to said filament.

References Cited in the file of this patent UNITED STATES PATENTS 976,287 Phelps Nov. 22, 1910 1,842,167 Hall Jan. 19, 1932 2,304,888 Davis Dec. 15, 1942 2,442,845 Davis June 8, 1948 2,509,809 Cook May 30, 1950 

1. A CANDLE-SIMULATING ELECTRIC LIGHT COMPRISING IN COMBINATION A LIGHT-TRANSMITTING, FLAME-SHAPED BULB, A FILAMENT RESISTANCE WIRE MOUNTED WITHIN SAID BULB, AN INTERMITTENT AND NON-UNIFORM ACTING THERMAL SWITCH INCLUDING A FIRST ELONGATED THERMAL RESPONSIVE ELEMENT, A SECOND ELONGATED ELEMENT, A NON-CONDUCTING BASE, MEANS IN SAID BASE FOR SUPPORTING SAID ELEMENTS BY ONE OF THEIR RESPECTIVE ENDS IN CONTIGUOUS RELATIONSHIP AND FOR ALLOWING EASY VIBRATION OF SAID ELONGATED ELEMENTS WITH RESPECT TO EACH OTHER AND TO SAID BASE, A CONTACT AT EACH OF THE OTHER ENDS OF SAID ELONGATED ELEMENTS IN COOPERATING RELATIONSHIP TO EACH OTHER, AND A HEAT-PRODUCING RESISTANCE WIRE THERMALLY ENGAGED WITH ONE OF SAID ELONGATED ELEMENTS AND ELECTRICALLY INTERCONNECTED BETWEEN SAID ELONGATED ELEMENTS FOR PRODUCING HEAT WHEN SAID CONTACT ARE DISENGAGED, SAID ELONGATED ELEMENTS BEING SIZED TO VIBRATE FREELY UPON A BREAK IN CONTACT BETWEEN SAID CONTACTS TO PRODUCE ALTERNATE ENGAGEMENT AND DISENGAGEMENT OF SAID ELONGATED ELEMENTS IN A RAMDOM PATTERN, A FIRST POWER LEAD CONNECTED TO ONE SIDE OF SAID FILAMENT WIRE, CONDUCTING MEANS CONNECTING ONE OF SAID ELONGATED ELEMENTS OF SAID SWITCH TO THE OTHER SIDE OF SAID FILAMENT WIRE, AND A SECOND POWER LEAD CONNECTED TO THE OTHER OF SAID ELONGATED ELEMENTS OF SAID THERMAL SWITCH FOR SUPPLYING ELECTRIC CURRENT TO SAID SWITCH AND INTERMITTENTLY TO SAID FILAMENT. 